[Amps] FW: RF Chokes

[R L Measures]

  :

From: R L Measures <r at somis.org>
Date: July 18, 2006 6:31:07 PM PDT
To: "Phil Clements" <philc at texascellnet.com>
Subject: Re: [Amps] FW:  RF Chokes


On Jul 18, 2006, at 1:53 PM, Phil Clements wrote:

>
>
>
>  Subject: RE: [Amps] RF Chokes
>
>  This is not as bad as many Internet suggested mods are,
>  since the additional C at the bottom of the choke won't
>  hurt.

1000pF bypassing the typical 1.5A-rms of  160m current in the HV-RFC  
allows over 100V-rms of 1.8MHz energy to enter the HV-PS.  Is this  
good engineering practice in your opinion, Tom?

> Unfortunately some mods on Websites actually hurt
>  reliability, but this suggestion is benign. The bad ones
>  include resistor grid fuses,

Since Fall, 1988, no one who has installed the frangible grid-fusing  
resistors that comes with our low VHF-Q suppressor retrofit kits has  
reported having a 3-500Z grid-filament short or a 572B or 811A  
shatter its filament.

> increasing power supply capacitance,

Good point, Tom.  Increasing power supply stored J requires  
increasing the J-capability of the glitch R.

> and removing caps across diodes,

What function do such caps serve at 50 - 60 Hertz?

> and increasing resistance across electrolytics.

In the Sprague electrolytic cap data sheets, there is no formula for  
calculating the resistance of the equalizing resistors.  As I see it,  
if the voltages measured across the caps during use are within a few  
percent, and the caps bleed down in approximately the time needed to  
drink a Becks, the R is right.
>
>  Food for thought...

Indeed, Tom, indeed.
>
>  73 Tom
>

R L MEASURES, AG6K. 805-386-3734
r at somis.org




R L MEASURES, AG6K. 805-386-3734
r at somis.org